Power draw of Cartoonifier running on desktop versus embedded system

We've seen that various embedded devices are slower than desktops, from the Raspberry Pi 1 being roughly 20 times slower than a desktop, up to Jetson TK1 being roughly 1.5 times slower than a desktop. But for some tasks, low speed is acceptable if it means there will also be significantly lower battery draw, allowing for small batteries or low year-round electricity costs for a server, or low heat generation.

Raspberry Pi has different models even for the same processor, such as Raspberry Pi 1B, Zero, and 1A+, which all run at similar speeds but have significantly different power draws. MIPI CSI cameras such as the Raspberry Pi Cam also use less electricity than webcams. The following table shows how much electrical power is used by different hardware running the same Cartoonifier code. Power measurements of Raspberry Pi were performed as shown in the following photo using a simple USB current monitor (for example, J7-T Safety Tester (http://bit.ly/2aSZa6H) for $5) and a DMM multimeter for the other devices:

Idle power measures power when the computer is running but no major applications are being used, whereas Cartoonifier power measures power when Cartoonifier is running. Efficiency is Cartoonifier power/Cartoonifier speed in a 640 x 480 sketch mode:

We can see that Raspberry Pi 1A+ uses the least power, but the most power efficient options are Jetson TK1 and Raspberry Pi 3B. Interestingly, the original Raspberry Pi (Raspberry Pi 1B) has roughly the same efficiency as an x86 laptop. All later Raspberry Pis are significantly more power efficient than the original (Raspberry Pi 1B).

Let's also look at the power draw of different cameras that work with Raspberry Pi:

We see that Raspberry Pi Cam v2.1 is slightly more power efficient than Raspberry Pi Cam v1.3 and significantly more power efficient than a USB webcam.